Computers and your eyes

USING YOUR EYES AND YOUR VDT

It's 1l:30 in the morning. You've been working at your video display terminal (VDT) since 9:OO AM. Your eyes feel irritated and fatigued your vision is blurry and you still have several hours of work ahead of you.

The symptoms that you are experiencing are common among people who work with VDTs. They may be a result of the way that you use the equipment and furnishings in your workstation. But they may also be at least partly the result of' a vision problem. Anytime you experience symptoms like headaches eye strain blurred vision eye irritation double vision excessive tears or dry eyes pain in the eyes or excessive blinking or squinting you should visit your doctor of optometry for a comprehensive eye examination. And when you do be sure to tell the doctor about the VDT work that you do.

Alter you have had comprehensive eye examination, there are a number of things that you can do to arrange and use the elements of you workstation to eliminate or minimize discomfort.

ADJUSTING YOUR CHAIR

Many times, your chair can be adjusted to make your work station much more efficient and comfortable. For instance:

Your feet should be flat on the floor (or on a slightly angled foot rest) with your knees bent neat or greater than 90 degrees.
Your seat should support your legs without excessive pressure on the back of your thighs.
Your back should be snug against the seat to fit your spinal contour. Your thighs to trunk angle should be 90 degrees or greater.
The distance from the front of your chair to the hollow of your knee should be 2” to 4” inches.
Your wrist and hand should extend nearly straight form the elbow to the home row of the keyboard.

SETTING UP YOUR WORK SURFACE

Consider the following suggestions to make sure the height of your work surface and the amount of leg room it provides are “comfortable.”

For most people, the amount of legroom below the work surface should be about 25” high by 27” wide by 27” deep. Larger people will require more space.
A commonly preferred work surface height for VDT use is about 26” as opposed to conventional 29” of most tables or desks.

USING YOUR VDT AND KEYBOARD

The following suggestions will help you arrange your VDT screen and your keyboard to allow you to work most productively and comfortably:

Locate your VDT 16” to 30” from your eyes, depending on the size of your individual vision conditions. Many people find 20” to 26” most comfortable.
The top of the VDT should be slightly below a horizontal eye level. Tilt the top of the VDT away from you at a 10-degree to 20-degree angle.
Place document holders close to your screen within the same viewing distance. Keep your keyboard and VDT in line.
Keep you VDT screen free of fingerprints and dust. Both can reduce clarity.
Adjust your keyboard so it does not lie flat.

VDTs AND LIGHTING

To improve visual efficiency when using your VDT:

Try to match the brightness of the surroundings to that of the VDT screen. Overall room light should be about 20 to 70-foot candles, which is about half the level of normal office light.
The contrast between the characters on the VDT screen and the screen background should be high.
Minimize reflected glare on your VDT screen by using window treatments, dimmer switches on lights and anti-glare screens.
Position your VDT screen perpendicular to windows or other bright light sources to reduce the likelihood of glare. To locate the source of blare, hold a small mirror on your VDT screen. The reflection will help you determine the origin of the glare.

WORKING EFFICIENTLY

Human eyes were made for most efficient operation at a distance, but if you use the suggestions make here and those make by your doctor of optometry, you will be able to use your VDT more comfortable and productively.